Direct current dynamo-electric machine



Jan. 3, 1933. w, HETER' 1,893,367

DIRECT CURRENT DYNAMO ELECTRIC MACHINE Fi led Jan. 50, 1952 inventor": I I i a Heater, y mww His Attorney.

35 of sufficient alternating current magnetic ing two outer symmetrical sides 10 and an ternating current magnetic flux to give the tending through notches 12 thereimand the 59 chinehaving a stationary member including ing flat inner surfaces, a magnet frame of Patented Jan. 3,1933 I 1,8933%? earner erriei:

uNrrr. STATE WYLIE Harris, or SCOTIA, new YORK, assrenon ro GENERAL ELECTRIC COMPANY, A CORPORATION or nnw YORK i manor CURRENT DYNAMO-EL-EGTRIC MACHINE Application filed January 30, Serial No. 583,957.

My invention relates to directcurrent dya magnet frame, and laminated structure ex namo-electric machines. tending about the periphery of the magnet In the operation of direct current generframe which will carry sufficient alternating ators, it is sometimes desirable to utilize the current magnetic flux to start the machine generator asa single phase alternating curas a sing e phase alternating current motor. rent motor; This is particularly true in case In the drawing, Fig. 1 is a fragmentary ofdirect current generators which are driv end view of a. direct current dynamo-electric on by alternating current synchronous momachine embodying-my invention, and Fig. tors, and where'direct current isnot avail- 2 is a perspective view, of part of the lamiable for. utilizing thegenerator as a fstarti'ng nated structure shown in Fig. 1.

motor, so that the alternating current motor Referring to Fig. 1, I have shown my incan be brought up to synchronous speed and vent-ion embodied in adirect current dynaconnected to a source of alternating current mo-electric machine having a rotatable memfor driving the direct current generator. It her 1 mounted on a shaftQ, and a stationary has been proposed, heretofore, to provide an member including main field poles 3 and com alternating current starting motor for bringmutating poles 4 extending radially inward ing the motor and generator set up to synfrom a magnet frame 5, and secured thereto chronous speed, but this involves the cost of by bolts 6 and 6' respectively. I an additional machine. Furthermore, in In accordance with my invention, the masome installations, where space is of primary chine is constructed so that the field strucimportance, such as in electrically driven ture willcarry sufficient alternating current locomotives, for example, the useof a startmagnetic flux to give the necessary starting ing motor is quite undesirable. For these torque when it is operated as a single phase reasons, it is desirable to eliminatethe use alternating current motor. I do ,thisby proof a starting motor for bringing the synvidingalaminated structure extending about chronous motor and-direct current generator the entire inner periphery of the magnet up to the synchronous speed of the motor. frame 5, and extending between the magnet It has not beenpossible to operate the ordiframe, and the main poles 3 and commutating nary type of direct current generator as a poles 4. This laminated structure comprises single phase alternating current motor in a a number of arcuate shaped bodies 7 riveted system of this type for bringing the synat8'and having a curved outer surface9, as chronous motor up to speed, however, beshown in Fig. 2, which is adapted tofit closecause the eddy currents in the solid field ly against the inner'periphery of the magnet frameof the machine prevent the building up frame 5, and a three sidedinner surface havflux to give the necessary starting torque. intermediate side 11, these sides being made For this reason, the difficulties encountered large enough to provide a flat shoulder for in obtaining the required starting torque the windings on the poles of the machine. have made it impracticable to operate direct The laminated bodies 7 are arranged end to 49 current generators as single phase alternatend about the inner periphery of the magnet ing current motors. frame 5, with eachglaminated body extend- The object of my invention is to provide a ins between the centers of two adjacent main direct current dynamo-electric machine field poles which are secured to the sides which is capable of building up sufficient al- 10 of two adjacent bodies by the bolts 6 exnecessary starting torque, so that the machine commutating poles 4 are secured against the can be operated as a. single phase alternating sides 11 bv the bolts 6 extending through current motor. I accomplish this bv proopenings 13. r viding a direct current dynamo-electric ma- B emoloving'the laminated bodies 7 havminimum outside diameter can be used because the rivets 8 can be placed in the thickest sections of the bodies, so that they will not reduce the cross sectional area of the flux path through the bodies. Furthermore, the particular shape of the laminations insures,

high mechanical strength of the bodies 7, so

' that they can be handled and assembled between the poles and the magnet frame with-' out any difficultyl In this way, the size of vthe machine is not appreciably increased, and at the same time the stationary member has ample strength and stiffness.

For the purpose of reducing the size of this machine, so that it will occupy the minimum amount of'space, I prefer to use the least amount of material in the laminated structure which will produce the required flux in the air gap for starting-the machine on alternating current. I have found that the necessary torque for starting a machine on alternating current can be obtained by using a quantity of materialwhich will carry a fiux approximately ten per cent of that normally required for ordinary operation of the machine as an alternating current motor.

Inaddition to enabling a direct current V dynamo-electric machine to start on altera nating current, this construction also. im-

proves commutation during direct current' operation of the machlne, because the lami-- nated structure,-which forms a magnetic circuit for the commutating poles, permits fas-n ter shifting of flux with changesof load. In this-manner, the commutating poles are made magnet frame and said field poles for carry magnet frameand secured thereto for carrying sufficient alternating current mag:

'netic flux for starting said machine as a single phasealternating current motor.

4. A direct current dynamo-electric machine having a stationary member includ ing a magnet frame, a plurality of arcuate shaped laminated bodies extending end .to

end about the entire inner. periphery of said 1 magnet frame and secured-thereto, the inner surfaces of said bodies having fiat sides, and field poles-secured to thefiat sides of said laminated bodies; 7

Inwitness whereof, I have hereunto, set

my hand. c d 1 I p Y WYLIE 'HETER.

more effective tofurnish the proper amount of fluxto counteract the effect of the armature magnetomotive forces in the zone of commutation. p

' Modifications of the embodiment of my in vention which I have described will occur to those iskilledin the art, so that I desire my inventionnot to be limited to the particular arrangement set forth, and I intend in the claims to cover .all modifications thereof which do not departfrom the spirit and scope of my inventio I What I claim as newand desire to secure I by Letters Patentof the United States, is:

1. direct gcurrent dynamo-electric ma chine havlng a stationary member includmg a magnet frame, and means comprising laminated structure extending about the pe-' riphery of said magnet frame and secured thereto for carrying sufiicient. alternating current magnetic flux for starting said ma chine as a single phase alternating current motor. l r

'2. A direct current dynamo-electric machine having a stationary member including amagnet frame provided with-field poles extending radially inward therefrom, vand means comprising laminated structure extending about the inner periphery of said magnet-frame and extending between said. 

